Method and apparatus for reproducing a subject to be transferred to a rubber blanket for letterpress and offset printing and the like



Jan. 25, 1966 w. WANIELISTA METHOD AND APPARATUS FOR REPRODUCING ASUBJECT TO BE TRANSFERRED TO A RUBBER BLANKET FOR LETTERPRESS 7 ANDOFFSET PRINTING AND THE LIKE Filed Feb. 12, 1963 6 Sheets-Sheet 1 WqlerBY A;TORNEYS Jan. 25, 1966 w. WANIELISTA METHOD AND APPARATUS FORREPRODUCING A SUBJECT TO BE TRANSFERRED TO A RUBBER BLANKET FORLETTERPRESS AND OFFSET PRINTING AND THE LIKE 6 Sheets-Sheet 2 Filed Feb.12, 1965 m T. m V m PVa/ar m' ga m BY w;%% a,

ATT NEYS Jan. 25, 1966 w. WANIELISTA 3,230,322

METHOD AND APPARATUS FOR REPRODUCING A SUBJECT TO BE TRANSFERRED TO ARUBBER BLANKET FOR LETTERPRESS AND OFFSET PRINTING AND THE LIKE FiledFeb. 12, 1965 6 Sheets-Sheet 5 INVENTOR.

A TTO E YS Jan. 25, 1966 w. WANIELISTA 3,230,822

METHOD AND APPARATUS FOR REPRODUCING A SUBJECT TO BE TRANSFERRED TO ARUBBER BLANKET FOR LETTER-PRESS AND OFFSET PRINTING AND THE LIKE 6Sheets-Sheet 4 Filed Feb. 12, 1963 umu lHT l I NVENTOR. Wcgler Wmgz'e swATTO NEYS Jan. 25, 1966 w. WANIELISTA 3,230,822

METHOD AND APPARATUS FOR REPRODUCING A SUBJECT TO BE TRANSFERRED TO ARUBBER BLANKET FOR LETTERPRESS AND OFFSET PRINTING AND THE LIKE FiledFeb. 12, 1963 e Sheets-Sheet 5 IN VENTOR @g%- A TTOR YS Jan. 25, 1966 w.WANIELISTA METHOD AND APPARATUS FOR REPRODUCING A SUBJECT TO BETRANSFERRED TO A RUBBER BLANKET FOR LETTERPRESS AND OFFSET PRINTING ANDTHE LIKE 6 Sheets-Sheet 6 Filed Feb. 12, 1965 9 me w%w m Mm I. m 1 r T@JJ H IIWWIFEL United States Patent METHOD AND APPARATUS FOR REPRODUCINGA SUBJECT TO BE TRANSFERRED TO A RUBBER BLANKET FOR LETTERPRESS ANDOFFSET PRINTING AND THE LIKE Walter Wanielista, Westchester, Ill.,assignor to Robertson Photo-Mechanix, Inc., Chicago, 111., a corporationof Illinois Filed Feb. 12, 1963, Ser. No. 258,034 Claims. (CI. 88-24)This invention relates to improvements in an apparatus for reproducing asubject to be transferred to a piliinting plate for letter press andoffset printing and the li e.

In printing from a rubber blanket printing plate in which the printingsurface is offset from the body of the plate, Where the blanket plate orother printing plate has an impression printed thereon and is curvedabout a blanket or press cylinder of a printing press, to transfer theimpression to sheets of paper, the curving of the blanket about thecylinder distorts the impression, with a resultant imperfect printedimpression on the paper. This occurs in all relief printing platesplaced about press cylinders, including conventional forms offlexographic, rubber dry oflset plates, and relief zinc and magnesiumprinting plates.

A principal object of the present invention, therefore, is to provide anovel, simple and improved apparatus correcting the distortion of theimpression made by a rubber printing blanket or other offset printingplate caused by curving the plate about a press cylinder.

A still further object of the invention is to provide a simple apparatusfor correcting the distortion of rubber blanket printing plates andother offset plates cause by curving of the plates about printingcylinders, comprising a holder for the subject to be impressed on theblanket with means for tilting the holder at an angle with respect tothe vertical determined by the distortion of the image on the plate,together with separate means for tilting the lens of the camera at thesame angle as the angle of the holder and locating means for thenegative in the camera for accurately locating the negative with respectto the subject together with other locating means associated with theholder for the negative, accommodating the negative to be supported onthe holder in an upside down position in accurate location with respectto the camera lens and negative, for reproducing the upside downnegative when the lens and holder therefor are tilted at equal angles.

A still further object of the invention is to provide a simplified formof adapter kit for adapting graphic arts cameras and copyboards tocompensate for the distortion of the impression on rubber blanketprinting plates or other offset printing plates when curved about aprinting cylinder.

These and other objects of the invention will appear from time to timeas the following specification proceeds and with reference to theaccompanying drawings where- FIGURE 1 is a view in side elevation of acamera and copyboard assembly embodying the distortion correctingapparatus of the present invention;

FIGURE 2 is a diagrammatic view illustrating certain principles of thepresent invention and showing the positions of the lens and copyboardfor making a first negative, and also the form of the impression on thefirst negative;

FIGURE 3 is a diagrammatic view illustrating the positions of thecopyboard and film for taking a second negative and showing theimpression on the final negative, to be used to transfer to a rubberblanket;

3,230,822 Patented Jan. 25, 1966 "ice FIGURE. 4 is an enlarged view inside elevation of the support and tilting means for the copyboardshowing the copyboard supported thereon;

FIGURE 5 is a fragmentary front view of one side of the carriage for thecopyboard showing the mechanism for tilting the copyboard, and showingthe copyboard in broken lines;

FIGURE 6 is a fragmentary view in side elevation of the forward endportion of the camera showing the tilting mechanism for tilting thecamera lens;

FIGURE 7 is a fragmentary front end view of the camera, looking at thelens and the tilting mechanism therefor;

FIGURE 8 is a front end view of the chase for mounting the distortednegative on the copyboard, to be rephotographed in an upside downposition;

FIGURE 9 is a partial fragmentary sectional view taken substantiallyalong line IXIX of FIGURE 8 and drawn to an enlarged scale; and

FIGURE 10 is an enlarged fragmentary sectional view taken substantiallyalong line XX of FIGURE 8.

In the embodiment of the invention illustrated in the drawings, I haveshown in FIGURE 1 a graphic arts camera 10, which may be a reflexcamera, and is shown as being mounted at one end of a track 11 and ashaving a lens 12. I have also shown a copyboard 13 adjustably mounted onthe track 11 for movement towards and from the lens 12 with its centerin alignment with the optical center line of the lens 12. Lights 15 infront of the copyboard l3 and on opposite sides of the track 11 areprovided to project light to illuminate a subject on the copyboard byreflection. I have further shown a light 16 for projecting light throughthe back of the copyboard through a chase l7 thereon and illuminating anegative carried by the chase for reproducing the negative by thecamera.

When normally photoreproducing a subject, the subject to be reproducedis placed in the copyboard and the copyboard is positioned verticallywith its center in alignment with the optical center of the lens. A film14 then is placed in the camera and exposed and developed. The image onthe negative will be of a size substantially like that diagrammaticallyshown by solid lines in FIGURE 3.

In accordance with the principles of the present invention, the film ispunched as indicated by reference character 18 and the punched portionsof the film are registered with pins 19 within the camera. This willaccurately locate the film with respect to the copyboard. The copyboardis then rotated in a clockwise direction an amount determined by thedistortion caused by the curving of the rubber blanket printing plate asplaced on the press cylinder. The angle of tilt of the copyboard mayusually be 10 from the vertical. The lens 12 may also be tilted withrespect to the vertical in a. clockwise direction at the same angle asthe angle of the copyboard. The subject to be reproduced being placed onthe copyboard 13 in centered relation with respect thereto isilluminated by reflection by the lights 15 and the film on the pins 19is exposed by opening the lens shutter (not shown). The exposed film isthen developed to produce a negative, and when developed the image onthe negative will cover an area indicated by dotted lines in FIGURE 2.

The negative is then placed on the chase 17 and registered on pins 20,20 on the chase. The chase is placed upside down on the copyboard whentaking the second picture, so the top of the negative is at the top. Asecond film properly punched is then registered with the pins 19 in thecamera. With the lens 12 and copyboard 13 tilted at the same angle asfor the first exposure, the first negative is illuminated by the light16 projecting light through the back of the copyboard and chase. Thesecond film is then exposed and developed. The width of the impressionon the second film will be the same as the width of the impression onthe first film, but the length of the impression on the second film willbe equal to the length of the impression on the first film plus anadditional amount indicated by D, the distance D equalling the amount ofdistortion of the image on the rubber blanket printing plate when curvedabout the blanket or impression cylinder ofthe printing press.

It may thus be seen that by the apparatus and system of the presentinvention, distortion of the impression placed on a rubber blanket bythe curving of the blanket plate about a blanket or impression cylinder:has been compensated for and that the blanket plate with the correctedimpression thereon may readily be curved about its impression cylinderand print an imrpession on paper free from distortion.

Referring now in particular to certain detailed features of theinvention, the copyboard 13 may be a conventional form of copyboardcommonly used for copying subjects for impression on rubber blanketplates or other plates for printing, and includes a generally U-shapedcarriage 23 mounted on the track 11 for adjustable movement therealongand having parallel spaced upstanding side arms 24 having the copyboard13 pivotally mounted therebetween on trunnion pins 25, as shown inFIGURES 1 and 5, only one of said side arms and trunnion pins beingshown herein. The copyboard 13 includes generally a cover or frontsection 26 and a back or base section 27. The trunnion pins 25, 25extend laterally from opposite sides of the base section. The frontsection 26 is suit- .ably hinged to the back section 27 to accommodateopening of the copyboard to place a subject to be reproduced in thecopyboard, and has a glass plate (not shown) extending a-crossthe frontthereof.

The back section may also have a glass plate (not shown) extendingacross the back thereof and may have a felt (not shown) mounted thereonupon which the chase or subject to be reproduced may be mounted. Thefelt may have an open central portion to accommodate the light 16 toproject light through the back of the copyboard and illuminate anegative carried by the chase 17. The copyboard itself may be ofanyconventional form and is well known to those skilled in the art soneed not herein be shown or described further.

Referring now in particular to the means for tilting the copyboard 13when it is desired to correct for distortion caused by curving of arubber blanket plate as placed on a blanket or impression cylinder, asshown in FIGURES 4 and 5, the right hand side arm 24 has a slot 30therein opening toward the camera 10. The slot 30 is adapted to receivea hollow pin 31 extending inwardly from a pivot plate 32 pivotallymounted on the trunnion pin 25 (FIGURE The pivot plate 32 has a boss orsleeve 33 extending inwardly of its upper end portion and abutting aboss 35 extending outwardly of the side arm 24. The bosses 33 and 35space the pivot plate 32 outwardly of the side arm 24 to dependvertically from the pivot pin 25.

The sleeve or hollow pin 31 has a pin 36 extending therealong inwardlyof the side arm 24 and adapted to have connection with the back section27 of the copyboard 13. A knob 37 is mounted on the outer end of the pin36. The pin 36 may be releasibly mounted in the sleeve 31 in a suitablemanner (not shown) to accommodate release of the pin 36 from the backsection 27 of the copyboard 13 when it is desired to move the copyboardto a horizontal position.

The pivot plate 32 has an arcuate slot 39 formed therein, the arc ofwhich is struck from the center of the pin [25. A locking shaft 38slidably extends through said slot and is threaded in a boss 40extending outwardly of the side arm 24 and having slidable engagementwith the inside of the pivot plate 32, at its outer side. A lock handle43 is secur d to the o t r e d of the lock shaft 41 f turning said shaftwithin the boss 40 and locking the pivot plate 32 in fixed position whenthe angle of the copyboard has been properly set. When the copyboard isset at the proper angle, the pivot plate may be locked in a fixedposition. The pin 36 may then be released to permit turning of thecopyboard independently of the pivot plate and to be reset at the angleof the pivot plate by engaging the pin 36 with the copyboard.

The pivot plate 32 and copyboard 13 are tilted by a traverse nut 44threaded on a screw 45 and connected with the pivot plate 32 by a linkin the form of a turnbuckle 46. The traverse nut 44 is guided betweenguide plates 47 of a traverse guide 48. The traverse guide 48 consistsof a base plate 49 mounted on the side arm 24 and extending thereacrossand having the guide plates 47 suitably secured to opposite sidesthereof and extending outwardly therefrom. End walls 50 and 51 closeopposite ends of the guide plate 47 and form bearing supports for thescrew 45. The screw 45 extends outwardly of the end wall 50 and has ahand wheel 53 mounted thereon for turning said screw and moving thetraverse nut 44 along the guide 48. The turnbuckle 46 is pivotallymountedat one end on a pin 54 extending horizontally outwardly of thetraverse nut 44 and is pivotally mounted on its opposite end on a pin 56extending outwardly of the lower end portion of the pivot plate 32.

The base plate 49 has a counter 55 mounted thereon connected with thethreaded shaft 45 through a coupling 57. The counter is provided tocount the revolutions and partial revolutions of the shaft 45 requiredto tilt the pivot plate 32 and copyboard 13 at a selected angle, toenable the operator to determine the angle of tilt of the copyboard andto tilt the copyboard at the same angle each time the board ispositioned to correct distortion.

The lens 12 is tiltable about the axis of laterally spaced coaxialtransverse pivot pins 59 forming mounting for a lens mounting plate 60and coaxial with the horizontal center line of the lens. A dial 61 isprovided to tilt the lens. The dial 61 is secured to an internallythreaded sleeve 62 having connectors 63 and 64 threaded in opposite endsthereof.

The internally threaded sleeve 62 and connectors 63 and 64 form ineffect a turnbuckle connecting a stationary plate 65 depending fromthelens mounting plate 60 with a movable lock plate 66 suitably secured tothe pin 59 for tilting the lens upon turning of the dial 61.

The mountings for the pivot pins 59 on each side of the lens plate arethe same, so one side only need therein be shown or described. As shownin FIGURES 6 and 7, the pivot pins 59 are mounted in laterally spacedbrackets 68 secured to and extending outwardly of a mounting plate 67.The mounting plate 67 is mounted on the front of the camera by thumbscrews 69 which also mount a bellows assembly 70 to the front of thecamera to extend forwardly therefrom.

The lens mounting plate is spaced in advance of the mounting plate 67and is connected with the lens bellows assembly through the bellows ofthe assembly and has the lens 12 mounted thereon in a conventionalmanner. The lens mounting plate 60 has spaced ears 73 projectingforwardly therefrom and mounted on the pivot pins 59 and connectedthereto as by set screws 7.4 (FIGURE 7).

As shown in FIGURE 6, the lock plate 66 extends forwardly of the pivotpin 59 and has a boss '75 extending outwardly therefrom abutted by theinside of the connector 64 and forming a mounting for a pivot pin 76 forsaid connector. The stationary plate 65 also has a hub or boss 77extending outwardly of its lower end portion and abutting at its outerend the inside of the connector 63 and spacing the axes of theconnectors 63 and 64 and sleeve 62 parallel to the plate 65. The boss 77forms a mounting for a pivot pin 79 pivotally connecting the connector64 to the plate 75.

The lock plate 66 is shown in FIGURE 6 as having an arcuate slot 80formed therein, the are of which is struck from the axis of the pivotpin 59. A pin 81 is mounted in the stationary plate 65 and extendsoutwardly therefrom through a hub or boss 83 and through the arcuateslot 80. The outside of the boss 83 abuts the inside of the lock plate66.

A lock knob 84 has a hub 85 formed integrally therewith and threaded onthe pin 81 and abutting the outside of the lock plate 66 to lock saidplate in position upon turning of the knob 84. The lock plate 66 has apointer 86 depending therefrom registering with indicia 87 in thestationary plate 65, to indicate the degree of tilting of the lens 12.

A pointer 88 is also mounted on the stationary plate 65 and registerswith indicia 89 on the dial 61 to enable the position of said dial to beascertained with respect to the angle of tilt of the lens 12 and toprovide a base enabling the dial to be turned back to the same positioneach time the lens 12 is tilted.

The chase 17 is in the form of a vacuum frame con structed along linessimilar to those shown and described in United States Patent No.3,028,786 granted to Walter Wa'nielista and Daniel Franklin Keller onApril 10, 1962, so need only herein be shown and described in sutficientdetail to render the present invention readily understandable.

The chase 17 is diagrammatically shown in FIGURE 3 as being mounted onthe base frame or back section of the copyboard and generally includes avacuum plate board 90 adjustably mounted on horizontally extending bars91, 91 adjacent the top and bottom of the copyboard and on spacedupright bars 92, 92 extending along opposite sides of the copyboard. Thevacuum plate board 90 is mounted on the upright bars 92, 92 in registrywith an open portion 94 of the base frame of the copyboard on links 93,93. A turnbuckle 95 is connected between the base frame for thecopyboard and an upright bar 92 to center the vacuum plate board 90 withrespect to the optical center of the lens and a central opening 96 ofthe copyboard prior to positively securing the chase in place on thecopyboard. Thumb screws 94, 94 (FIGURE 9) are provided to lock the links93' in position and to thereby lock the chase in centered relation withrespect to the copyboard.

The vacuum plate board 90 has a central rectangular opening 97 therein(FIGURE having a rectangular shoulder 99 extending outwardly therefromand forming a recess for a glass plate 100 which may be in the form of aclear glass plate. The glass plate 100* is sealed to the mar-gin of theopening 97 as by sealing putty 101. The plate 100 has a peripheral edgespaced from rectangular walls defining the outer margins of the shoulder99, and forming a peripheral vacuum passageway 102 extending about themargin of the glass plate 100. Vacuum is supplied to the passageway 102through suitable valve means (not shown) in a valve block 103 at theback of the glass 100 (FIGURE 10). The valve block 103 has communicationwith a plurality of slots or passageways 104 leading to the peripheralpassageway 102. The valve block 10 3 has a vacuum input (not shown)which may be connected with a suitable source of vacuum in aconventional manner.

As shown in FIGURE 9, a pin 105 extends outwardly of the valve block 103and has an arm 106 secured thereto. The arm 1% has an operating pin 107extending perpendicular thereto through an arcuate slot 109 formed inthe vacuum board 90 to accommodate operation of the valve fro-m theouter side of the vacuum board. The valve itself may be of any wellknown form and is no part of the present invention so need not herein beshown or described further.

The vacuum board 90 also has suitable masking 110 extending about theperiphery of the glass 100 and has the spaced pins 20, 20 extendingoutwardly therefrom and corresponding to the spacing of the pins 19, 19on the back of the camera for registry with the holes 18, 18

in the film to exactly register the film in the same position on thechase as in the camera, and to thereby accommodate the duplication ofthe subject on the first film as the position of the negative from thefirst film is placed upside down and the image on the negative isilluminated by the projection of light through the negative from theback of the copyboard by the light 16, as shown in FIG- URES 1 and 3.

During operation of the apparatus when correcting for distortion of animage to be impressed on a rubber blanket an unexposed film 14 is placedin the camera in registry with the pins 18, 18. The copyboard 13 is thentilted in accordance with the distortion of the image on a .printingplate when placed about the impression cylinder, which may be at anangle of 10. The lens is also tilted at an angle of 10 by operation ofthe dial knob 61. The subject to be photographed being placed on thecopyboard and held thereto by vacuum or by the pressure of the glass ofthe cover section 26, the film is exposed and developed and printed. Theimage on the negative, assumes the form indicated by the dotted lines inFIG- URE 2.

The chase 17 being mounted on the base frame of the copyboard, with thepins 20, 20 in an up position, the copyboard is rotated positioning thechase upside down with the pins 20 in the lowermost position shown inFIGURE 3. The developed film is then placed on the pins 20, 20 and whenso placed will be upside down from the position of the subject whenphotographed by the camera and is held to the chase by vacuum. Light isthen projected by the light 16 through the opening 96 in the base frameof the copyboard and through the negative carried on the pins 20, 20 ofthe chase. A second film is then mounted in the camera on the pins 19,19 and thus accurately located in the camera with respect to thenegative carried by the chase on the pins 20, 20. The second film isthen exposed and developed. The width of the impression will be the sameas the width of the original impression on the film, but the length ofthe impression will be the length of the original impression on thefirst film plus an additional distance D determined by the distortion ofthe image on a rubber blanket printing plate or other offset printingplate when placed on the impression cylinder.

While I have herein shown and described one form in which my inventionmay be embodied, it may readily be understood that various variationsand modifications in the invention may be attained without departingfrom the spirit and scope of the novel concepts of the invention.

I claim as myfinvention:

1. A graphic arts assembly for correcting the distortion of printingplates caused by curving of the plate about a printing cylindercomprising a frame, a camera at one end of said frame having a lenstiltable about an axis extending transversely of and intersecting itsoptical center, means in the camera engageable with the film foraccurately locating the film in the focal plane of the lens of thecamera, a copyboard on said frame in spaced relation with respect tosaid lens and having means on one side thereof for holding the subjectto be photographed and means on the opposite side thereof engaging anegative for accurately locating and holding the negative of the subjectphotographed in the same relation as the subject, means for tilting saidcopyboard at an angle sufiicient to compensate for the distortion causedby curving of the plate about its printing cylinder, means for tiltingsaid lens at the angle of tilt of said copyboard, said copyboard beingrotatable about an angle of 180 to position said means at the back ofsaid copyboard to face the lens of the camera and being open in thecenter thereof to accommodate the projection of light through a negativeon said locating means.

2. A graphic arts assembly for correcting the distortion of printingplates caused by curving the plate about a printing cylinder comprisinga frame, a camera at one end of said frame having a tiltable lens andhaving: means therein, means in the camera engageable with a film foraccurately locating the film in the focal plane of the camera, atiltable copyboard mounted on said frame and having means at one sidethereof for holding a subject to be photographed and having locatingmeans at the opposite side thereof engageable with a negative of thesubject photographed for accurately locating the negative with respectto the optical center line of the camera, means for tilting saidcopyboard at the angle required to correct for distortion caused bycurving of the plate about its printing cylinder, means for tilting saidcamera lens at the angle of tilt of the copyboard, means illuminatingthe subject to be photographed on said copyboard by reflection, saidcopyboard being rotatable about an angle of 180 to position a negativeon said locating means in fixed relation with respect to a film locatedon said camera and having an open portion accommodating the projectionof light therethrough, and means projecting through said open portion ofsaid copyboard.

3. A graphic arts assembly for correcting the distortion of offsetprinting plates caused by curving of the plate about a printing cylindercomprising a frame, a camera at one end of said frame, a lens for saidcamera, means mounting said lens for tiltable movement about an axisextending transversely of an intersecting the optical center of saidlens, said camera also having locating pins therein locating a film inthe focal plane of said lens, a copyboard mounted on said frame inspaced relation with respect to said camera for tilting movement aboutan axis extending transversely of said frame, said copyboard having afront cover section openable to accommodate the mounting of a subject tobe photographed in said copyboard and having a back frame, a chasemounted on said back frame and having pins thereon in the same spacingwith respect to the optical center of the camera as the pins in saidcamera for accurately locating a negative with respect to a film locatedon said pins in said camera, said copyboard also having an open centralportion to accommodate the projection of light through a negativelocated on said pins on said chase, means for tilting said copyboard atan angle determined by the stretch of said blanket when placing saidblanket about a printing cylinder, means for holding said copyboard inits tilted position, means for tilting said lens at the angle of tilt ofsaid copyboard and means for holding said lens at the angle of tilt ofsaid copyboard.

4. A graphic arts assembly for correcting the distortion of offsetprinting plates caused by curving of the plate about a printing cylindercomprising a frame, a camera at one end of said frame, a lens for saidcamera, means mounting said lens for tiltable movement about an axisextending transversely of and intersecting the optical center of saidlens, said camera also having locating pins therein locating a film inthe focal plane of said lens, a copyboard mounted on said frame inspaced relation with respect to said camera for tilting movement aboutan axis extending transversely of said frame, said copyboard having afront cover section openable to accommodate the mounting of a subject tobe photographed in said copyboard and having a back frame, a chasemounted on said back frame and having pins thereon in the same spacingwith respect to the optical center of the camera as the pins in saidcamera for accurately locating a negative with respect to a film locatedon said pins in said camera, said copyboard also having an open centralportion to accommodate the projection of light through a negativelocated on said pins on said chase and being rotatable through an angleof at least 180 to bring a subject on said chase to face said lens in anupside down position, a pivot plate pivoted for movement about the axisof pivotal movement of said copyboard, a pin releasably connecting saidpivot plate with said copyboard, a traverse guide having a screwextending therealong, a traverse nut guided in said guide and threadedon said screw, a link connecting said nut with said pivot plate, andmeans for locking said pivot plate in position to accommodate release ofsaid pin and accommodate turning of said copyboard free from said pivotplate, and to engage said pinwith said copyboard to position saidcopyboard in the same location atthe termination of changing theposition of said copyboard independently of said pivot plate.

5. A graphic arts assembly for correcting the distortion of the imagesof offset printing plates caused by curving of the plate about aprinting cylinder comprising a frame, a camera at one end of said frame,a lens for said camera, means mounting said: lens for tiltable movementabout an axis extending transversely of and intersecting the opticalcenter of said lens, said camera also having locating pins thereinlocating a film in the focal plane of said lens, a copyboard mounted onsaid frame in spaced relation with respect to said camera for tiltingmovement about an axis extending transversely of said frame, saidcopyboard having a front cover section open-- able to accommodate themounting of a subject to be photographed in said copyboard and having aback frame, a chase mounted on said back frame and having pins thereonin the same spacing with respect to the optical center of the camera asthe pins in said camera for accurately locating a negative with respectto a film located on said pins in said camera, said copyboard alsohaving an open central portion to accommodate the pro jection of lightthrough a negative located on said pins on said chase and beingrotatable through an angle of at least to bring a subject on said chaseto face said lens in an upside down position, a pivot plate pivoted formovement about the axis of pivotal movement of said copyboard, a pinreleasably connecting said pivot plate with said copyboard, a traverseguide having a screw extending therealong and a traverse nut threadedthereon and guided for movement along said traverse guide, a linkconnecting said traverse nut with said pivot plate to tilt saidcopyboard upon rotation of said screw, means locking said pivot plate inposition, means for tiltingv said lens at the angle of tilt of saidcopyboard comprising traverse pivot pins supporting said lens fortilting movement, means securing said lens to at least one of said pivotpins, a lock plate secured to said pivot pin, a stationaryplate securedto the camera, an extensible link connecting said lock plate to saidstationary plate, a dial for extensibly or retractibly moving said link,and thereby tilting said lens, and means for locking said lock plate instationary relation with respect to said stationary plate and therebylocking said lens in tilted position to correspond to the tilt of saidcopyboard.

References Cited by the Examiner UNITED STATES PATENTS 1,410,127 3/ 1922Roussilhe 8824 1,853,072 4/1932 Morioka 8824 2,512,182 6/1950 Sussin8824 2,607,268 8/1952 Bartz 8824 3,022,076 2/1962 Kargl 8824 NORTONANSHER, Primary Examiner. WILLIAM MISIEK, Examiner.

VANCE A. SMITH, Assistant Examiner.

1. A GRAPHIC ARTS ASSEMBLY FOR CORRECTING THE DISTORTION OF PRINTINGPLATES CAUSED BY CURVING OF THE PLATE ABOUT A PRINTING CYLINDERCOMPRISING A FRAME, A CAMERA AT ONE END OF SAID FRAME HAVING A LENSTILTABLE ABOUT AN AXIS EXTENDING TRANSVERSELY OF SAID INTERSECTING ITSOPTICAL CENTER, MEANS IN THE CAMERA ENGAGEABLE WITH THE FILM FORACCURATELY LOCATING THE FILM IN THE FOCAL PLANE OF THE LENS OF THECAMERA, A COPYBOARD ON SAID FRAME IN SPACED RELATION WITH RESPECT TOSAID LENS AND HAVING MEANS ON ONE SIDE THEREOF FOR HOLDING THE SUBJECTTO BE PHOTOGRAPHED AND MEANS ON THE OPPOSITE SIDE THEREOF ENGAGING ANEGATIVE FOR ACCURATELY LOCATING AND HOLDING THE NEGATIVE OF THE SUBJECTPHOTOGRAPHED IN THE SAME RELATION AS THE SUBJECT, MEANS FOR TILTING SAIDCOPYBOARD AT AN ANGLE SUFFICIENT TO COMPENSATE FOR THE DISTORTION CAUSEDBY CURVING OF THE PLATE ABOUT ITS PRINTING CYLINDER, MEANS FOR TILTINGSAID LENS AT THE ANGLE OF TILT OF SAID COPYBOARD, SAID COPYBOARD BEINGROTATABLE ABOUT AN ANGLE OF 180* TO POSITION SAID MEANS AT THE BACK OFSAID COPYBOARD TO FACE THE LENS OF THE CAMERA AND BEING OPEN IN THECENTER THEREOF TO ACCOMMODATE THE PROJECTION OF LIGHT THROUGH A NEGATIVEON SAID LOCATING MEANS.